Controller for wave guide tuner, phase shifter, or attenuator



United States Patent 2,774,946 I CONTRdLLER FORv WAVE GUIDE TUNER, 7PHASE SHIFTER, 'OR ATTENUATOR Clare D McG-illem and Frank Hasseld, Jr.,vindiana olis,.Ind., assignors to the United States of- America as'reresented'by the Secretary of the Navy Application March 12, 1954,-S'erial'No. 415,987

Claims. (Cl. 333-98) Grantediunder Title 35,. U. 5. Code 1952),sec.-266) The invention described'herein may be manufactured andused byenter the Government of the United States of America for governmentalpurposes without the payment of any royalties thereon or therefor.

This inventionrelates to waveguidesand more particularly to a meansforcontrolling a.conductive impedance element or a dielectric impedance.element within a rec'- tangular. waveguide from a point. externallythereof in a compact: manner to-contr0l the microwave energy thereinwithout producing any openings, cavities, or extensions within thewaveguideto otherwise deteriorate from o contaminate the microwaveenergy. V

In the known tuner, attenuator, and phase shifter controlling devicesfor waveguides, the controlling mechanism is a rather cumbersome pieceof' equipment supported externally of'the waveguide. In some of thesedevices one of the faces of the waveguide is slotted along the centerand the internal element is mechanically raised or lowered? into and outof the waveguide through the. slot; Other means of. single screw, singleslug, or multiple screw or slug controlling. devices are commonly usedwherein variations in the depth of the screws or slugs, or of thespacing of multiple screws or slugs, provide the control at" thesacrifice of cumbersome external manipul'ating means. Further; waveguideopenings or cavities for these screw or slugjmea'ns often: produceundesirable modification in-the microwave energy. The above knowndevices are usually madewith coarse adjustment means and" oftentimesdonot provide a smooth operation for control over the microwave energywhich is necessary'in precision use ofthecontrolling'elements.

In the present invention spaced circular openings are cut throughoneface of'a rectangular waveguide near a corner thereof. A pair ofdisk-s arerotatably mounted inl'the'se circular openings and are coupledt'og'eth'ento rotate: in unison". The innersurface of each-disk is flushwith the inner wall of the waveguide and each dish is eccentricallypivotally: connected on=itsinner face to an elongated planan' impedanceor microwave control" element, .the pivotal: points on th'e respectivedish'slyingin'the" same relative eccentriclposition whereby the' unitary rota tion of the disks carries the microwave control element to andfrom thexcentral; area of. the waveguide.- The microwavecontrolelen'ient is tapered on eachend toa halfi wave length in the:usual'rand ordinary manner of: construction ofi these elements. It: thedevice of themes: ent invention is used as a tuner, the materialof'theniicrowave controlelement: should be at good electrical conductor. Ifthedevice is used as an attenuator of'tli'e microwaves, the material ofthemicrowave: cont'rol' ele ment should be of.a lossy material, ascarbon. Poly styrene has been found to be the best materialfor'constructing the microwave control element where the device is to beused to phase'shi ft the microwaveenergyalthough most of the dielectricmaterialshaving a high dielectric constant may be used, where desired.It is therefore a general. object of this invention to provide a.compact manipulating'means for controlling'th'e microwave energy inrarectangular waveguide without making any obstructions or openingstherein to contaminate or deteriorate from the microwave energy.

These and other 'ohjects; advantages, features, and uses will becomemore apparent as: the description proceeds 2,774,946 Patented Dec. 18,1956.

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2" when considered with the accompanying drawing, in which:

Fig. 1. is a top elevational'partial view of a waveguide showing. theexternal. adjustable means of the impedance element in accordance withthis invention;

Fig. 2 is a view similar to Fig. 1 showing the impedance element in adiiferent'adjustedposition;

Fig. 3 is a side longitudinal cross-sectional view taken along'theline3'3'o'f Fig. 1;

Fig. 4 is a side longitudinal cross-sectional view taken along'theline44 ofFig'. 1;

Fig. 5 is a partial top'viewof the device shown in Fig. 1 showing anadditional meansv to drive the adjustable means;

Fig. 6 is a top plan view of a modified form of the adjustingmeans shownin Figs. 1 and 2; and

Fig. 7- is a top plan view of still another modification of theimpedance element'adjusting' means.

Referring more particularly to Figs. 1 to 4, there is showna=rectangularwaveguide 10 on one face of which is supported an adjustable means foran internal microwave control element. Two circular openings 11 and 12'rotatably support two-similar shouldered gears 13 and 14, the shoulders15 and. 16; respectively, of each resting against the outer surface ofthe waveguide 10 with the inner face of each being flush with the innersurface of the waveguide. The two-gears 13 and 14 are held againstmovement outwardly from the openings 11 and 12 by a retaining bracket 17having the outermost ends 18 and 19 tur'ned' at: right angles andpivotally set respectively in central sockets- 20'a nd 2 1 of gears 13'and 14. The retaining bracket 11 isheld in position by a studscrew 2i2'threaded in a' tapped opening ofthe waveguide equidi'stantly betweenthe two gears 13" and 14. The stud 22'- is shouldered at the en'd'of thethreaded portion to-h'o'ld the' retaining bar 17 i111 a:predeterminedpos'ition. Qn'the shank of the screw 22 b'etweentheretaining bracket 17 and the wall of the. waveguide 10 is an idler gear23 that meshes with both gears 13" and 14-. The idler gear-23 couplesthe gear-s'1'3-and'14 together to cause simultaneous rotation ofthese-two gears i'n'the same rotative direc= tion' and'at the sameangular. speed;

Each. of the gears 13 and-1'4' has a drilled opening ec centricallytherethrough in each'of which 'is fixed; as-Iby' cementingorpress'fitt'ing, a dielectric rodor pin 301 and"31,.respectively,'moreclearlyseen in Fig; 3'. Each rod is positioned atthe same radial distanceonu the respective: gear and in the same angularrelation. so; that they will movev in equal amounts over identical arcsfromtheside wallofthe waveguide upon actuation of the gears 13 and 14:.In ordento-arrange-the-ro'ds 30 and'31-to'operate betweenpositionsadjac'ent the side: wall. of the Waveguide and the centralarea: thereon-the openings and 12 are made near one corner ofthewaVeg'uide as shown! The rods 30-and 3l extend intorblin'd-bo'res. 32and 33; respec tively, of athinlmic'rowavecont'rol:element 34, best seeminFig:v 3. The element 34is-a thi-nastrip 'ofirnaterialithat: isslightly narrowerthanthe Waveguide ifinensideWalldi-fmensionto perm-it--it= to be A sl-idably-oarried' by the r rodsr30? and 31 laterally backand forth across the: Waveguide from: the waveguide sidewall.- to thecentral. area; as: seen in Fig. 2. The sidefaces of. the. element-3.4-alwaysremainparallel tothe sidewalls-of the waveguide-such that. inthe position where the element 34is fully withdrawn from the=centrallarea of the waveguideit isheld fiat againsttheside: wall 'andis' substantially ineffective on. the microwave. energy. Theeler'nent3'4is shownas a dielectric material such as polystyrene for the purpose.of illustrating theinventio'n althou h conductive material or earbonousmaterial may be" used where the device to fun 'on as a tuner or anat'tenuator, respectively. The'endsotthe Inent snare our at anangleferminga paraueleg'ram' the sides, as viewed in Figs. 3 and 4, asis the usual practice in controlling the phase of the microwaves, thesetapered portions being in the order of one half a wavelength of themicrowaves for optimum matching.

The teeth on the gears 13 and 14 serve as knurled portions for manually.manipulating the adjustment of the microwave control element 34, theactuation of either gear producing the adjustment. It may be desirablein some instances to actuate the adjustable means by a motordriven meansto produce cycling, or the like. In such instances a worm gear 36, asseen in Fig. 5, may be meshed with the gear teeth of one of the gears 13or 14 and rotated through an integral or fixed shaft 37. The worm gear36 and shaft 37 are supported in bearing supports 38 and 39 attached tothe waveguide.

The two gears 13 and 14 may be replaced by pulleys 40 and 41, as shownin Fig. 6. The pulleys are coupled together by a belt 42 whereby thepulleys rotate in unison to carry the microwave control element 34laterally back and forth in the waveguide. A driving or cycling meansmay be coupled to one of the pulleys in the same manner as shown in Fig.5.

As shown in Fig. 7, the gears 13 and 14 may be replaced by sprocketwheels 45 and 46 and coupled together by a chain 47. The rim of one orboth of the sprocket wheels could be toothed to provide knurled meansfor manual adjustment or to couple a driving or cycling means as shownin Fig. 5.

The operation of the waveguide controlling device is believed to beclear and apparent from the above description but a brief description ofoperation will be given herein for the convenience of reference. For anexample in describing the operation, let it be assumed that the deviceis a phase shifter wherein the microwave control element 34 should bemade of a dielectric material as polystyrene. In the position shown inFig. 1 the control element 34 is adjacent the side wall of the waveguidewhere substantially no phase shift is produced. By rotating either gear13 or 14 in either rotative direction the control element 34 will becarried in an increasing amount toward the center of the waveguide orthe extreme position, as shown in dotted lines in Fig. 2. The shift inphase of the microwaves passing through the waveguide is a continuouslyincreasing function as the distance of the control element 34 isincreased from the sidewall to the center, the maximum occurring whenthe control elemeat 34 is positioned in the central area of thewaveguide. The inner faces of the gears 13 and 14 provide a smoothcontinuation of the inner wall surface of the waveguide so that themicrowave energy is not altered in any way by the actuating mechanism.

Tuning can be accomplished in the same way where the microwave controlelement is of good electrical conductive material. Attenuation of themicrowaves in the waveguide may likewise be adjustably controlled byusing a lossy material as carbon, or the like.

While the preferred forms of the invention have been shown and describedherein, it is to be understood that many modifications and changes maybe made in the constructional details and features of this inventionwithout departing from the spirit and scope thereof and we desire to belimited only in the scope of the appended claims.

We claim:

1. In a waveguide a means for controlling the microwave energy thereincomprising, a pair of circular openings through a wall of the Waveguidein longitudinal relation, a pair of circular elements rotatablyjournaled in said circular openings respectively with the inner face ofeach flush with the inner surface of said waveguide and being coupled torotate in unison, and an elongated microwave control element in saidwaveguide and lying longitudinally thereof, said control element beingpivotally associated with said pair of circular elements at separatepoints whereby rotation of either circular element of said pair willshift said control element laterally in said waveguide.

2. In a rectangular waveguide a means for controlhng the microwavestherein comprising; a pair of circular openings through one wall of thewaveguide in longitudinal relation thereof; a pair of circular elements,one each being rotatably journaled in one each of said circular openingswith the inner face of each flush with the inner surface of saidwaveguide; means coupling said pair of circular elements for rotationthereof in unison; an elongated microwave control element within saidwaveguide lying longitudinally thereof; pivotal means connecting eachcircular element to said control element at spaced points; and means forrotating at least one of said circular elements of said pair wherebyrotation of said one of said pair of said circular elements will shiftsaid control element laterally of said waveguide.

3. A device as set forth in claim 2 wherein said circular openings are,of a diameter equal to substantially one-half the internal width of saidwaveguide and a sidewall of said waveguide is tangential to saidcircular openings, and said pivotal means is a rod extension on eachcircular element eccentrically and parallel to the axis of eachrespective circular element each extending into a bore in said controlelement.

4. A device as set forth in claim 3 wherein said means for rotating atleast one of said circular elements are gear teeth on the periphery ofsaid one element extending above and externally of said waveguide.

5. A device as set forth in claim 4 wherein said means coupling saidpair of circular elements for rotation in unison are gear teeth on theother of said circular elements extending above and externally of saidwaveguide and an idler gear meshing with the gear teeth of both saidcircular elements.

6. The device as set forth in claim 2 wherein said means coupling saidpair of circular elements for rotation in unison is an idler gearbetween said circular elements cooperative with gear teeth on theperiphery of said circular elements and said means for rotating at leastone of said circular elements of said pair is a worm gear in meshtherewith, said worm gear having a shaft extension thereon fortransmitting power from a rotational source.

7. A waveguide control device as set forth in claim 2 wherein said meanscoupling said pair of circular elements for rotation in unison is a beltpassed over pulley portions of each circular element exterior of saidwave guide.

8. A waveguide control device as set forth in claim 7 wherein said meansfor rotating at least one of said circular elements of said pair is aworm gear on a power input shaft in mesh with gear teeth on said onecircular element.

9. A waveguide control device as set forth in claim 2 wherein said meanscoupling said pair of circular elements for rotation in unison is achain passed over sprocket portions of each circular element exterior ofsaid waveguide.

10. A waveguide control device as set forth in claim 9 wherein saidmeans for rotating at least one of said circular elements of said pairis a worm gear on a power input shaft in mesh with gear teeth on saidone circular element.

References Cited in the file of this patent UNITED STATES PATENTS168,575 McCloskey Oct. 11, 1875 2,560,685 Cooper July 17, 1951 2,596,113Allebach May 13, 1952 2,602,893 Ratliff July 8, 1952 2,634,332 ZaleskiApr. 7, 1953 FOREIGN PATENTS 681,801 Great Britain Oct. 29, 1952

